Electric lamp with blackening collector



Jan. 17, 1950 1. H. VAN HORN ELECTRIC LAMP WITH BLACKENING COLLECTOR Filed Feb. 21, 1948 m H r e on n av r n Qw h w WU W H 9 .D

. Patented 17, 1950' ample morale LAMP WITH COLLECTOR momma Irving 1!. Van llorn, llltfiieveiand, Ohio, llsignor to General Electric Company, a corporation of New York Application February 21, 1948, Serial No. as

9 Claims. (Cl. 176-18) My invention relates in general to electric incandescent' lamps and more particularly to a mount structure therefor. Still more particularly, my invention relates to blackening collector means for such lamps and to a supporting arrangement therefor.

In gas-filled electric lamps having a filament of refractory metal such as tungsten, vaporized particles of the filament metal are carried by the convection currents within the. lamp bulb and are deposited on the walls of the bulb in the form of a dark coating which absorbs some of the light radiations from the filament and thereby reduces the luminous efliciency and the useful life of the lamp. Such bulb blackening, as it is commonly termed, is particularly objectionable in lamps designed for base 'down operation and wherein the light passing through the upper end of the bulb is to be used for indirect lighting purposes, since the blackening particles in such case aredeposited by the rising convection-currents principally on the upper bowl end of the bulb where it absorbs and reduces the amount of light available for indirect lighting.

It is one object or my invention to provide an electric incandescent lamp having means mounted therein for collecting the metal particles vaporized from the filament in order to reduce bulb blackening. Y

Another object of my inventionis to provide a lamp mount structure having blackening colreflecting shape such as. for instance, a paraboloid. The bulb l is preferably inside frosted and is provided with an internal light-diffusing coating -'l 0! the type disclosed in co-pending U. 8. application Serial No. 8'78 of Marvin Pipkln, filed January 7, 1948. and comprising a. layer of extremely fine particles of substantially pure silica deposited on the bulb wall by the combustion of an inflammable silicon compound within the bulb. The silica coating on the flattened top or end wall 5 oi the .bulhis preferably of lesser density than that on theflaring side wall portlon6. i- Mounted'within-the bulbil more orless symmetrically aboutthe bulb axis is an electric energy translationfelement orvfllament 8 of a refractory metaLsucIi as tungsten. The'fllament a illustrated comprises a coiled wire formed into horseshoe shape with the plane of thefllament extending transversely-'of'the bulb axis. The said filament is of relatively high wattage suchas, for instance, 150' watts or higher, and it is supported at its ends byia' pair of lead-in wires 5,10. The said leadi-in-wires 9, it are sealed in the press portion 4 o'r 'the stem 3, and out .wardly of the bulb are's'oldered or otherwise se- T cured to the'shell ii andeyelet it of a-base lector means of simple form and which can be quickly and easily mounted in place on the lamp mount.

Further objects and advantages of my 'iuvention will appear from the following description of a species thereof and from the accomying drawing in which:

Fig. 1 is an elevation, partly gas-filled electric incandescent lamp comprising my invention; Fig. 2 is an enlarged fragmentary view of the mount structure oi the lamp shown in Fig. 1; and Fig. 3 is a detailed perspective view of the blackening collector device accord ing to the invention.

Referring to the drawing, the lamp there shown comprises a sealed glass bulb l containing a gas filling, preferably consisting of argon with a small admixture of nitrogen, and having a neck portion 2 provided with a reentrant stem 3 having .a seal or press portion t. The particular bulb illustrated is provided with a flattened top portion 5 having a curvature of relatively large radius, and a flaring side wall portion 6 shaped in section, of a to conform to a surface of any desired optical 55 i3 securedto-the neck-Tend ci the bulb, as by cementing." The horseshoeeshaped filament t is further supported at; intermediate points along its length by one or more,,,anchor wires it the lower ends of which-are embedded in a ringshaped glass buttonlI-ili.iormedat-the upper end of a'tubular glass extension (pr-hollow arbor it extending upwardly fromgthe; stern press t in more or less alignment with the bulb axis. As shown more particularly in Fig. 2, the hollow interior ll of the glass arbor it forms a chamber which opens into the interior of the bulb. At its upper end, the glass arbor it is formed with an inturned annular lip it which, together with the portion it of the stem press closing the base end of the hollow arbor, provides spaced stop shoulders within the hollow interior of the arbor.

Mounted within the bulb l directly above the filament t is a blackening collector 2d of suitable iorm'which, in the particular case illustrated, comprises a disc-shaped perforate body, such as the wire screen element shown or a perforated metal sheet, disposed transversely of the bulb axis and completely overlying or capping the fileoperation. As shown in Fig. 1, the perforated body 20 is preferably of slightly dished or shallow frusto-conical form, with its under or concave side facing downwardly towards the filament 8.

In accordance with the invention, the blackening collector body 20 is supported in place within the bulb by a support member 2| comprising a length of wire of springy character, such as molybdenum wire for instance, suitably fastened at one end to the blackening collector, as by welding or pinching, and supported at its other end within the glass arbor l8. In the particular case shown, the wire support 2| is formed at its upper end with a right-angle bent end portion 22 which is welded to the fiat portion 23 of the wire screen element 20, with the wire support 2| extending perpendicularly from the said fiat portion 23 of, and more or less centrally or axially from, the disc-shaped screen element 20. At its other end, the wire support 2| is bent back upon itself to form a U-bend 24 therein and to provide a retroverted portion 25. The upper or free end of the said retroverted portion 25 of the wire support is bent at a slight angle less than 90, for instance 45 or thereabouts, to provide a spring finger 26 the free height of which (i. e., the projected distance between the bend 21 in the retroverted wire portion and the free end of the spring finger 26, measured laterally of the wire support 2|) is greater than the inside diameter of the hollow glass arbor I6. Also, the distance between the U-bend 24 in the wire support 2| and the free end of the spring finger 28 is made slightly less than the distance between the stop shoulders I8, l9 within the hollow glass arbor IS.

The blackening collector unit, comprising the wire screen element 20 and its support wire 2|, is assembled in place on the stem 3 simply by inserting the doubled-back end of the support wire 2| into the open end of the glass arbor l6 and pushing it through the arbor until the free end of the spring finger 26 passes beyond and snaps over the inturned lip or stop shoulder l8 on the arbor; In such position, the retroverted wire portion 25 of the support wire 2| is locked within the arbor. between the stop shoulders l8, l9 therein, whereby withdrawal of the support wire 2| from the arbor is effectively restrained. Since the free height of the spring finger 26 is greater than the inside diameter of the glass arbor IS, the spring finger, upon entering the hollow interior of the arbor, is compressed or flexed between the opposite 'sides of the inner wall of the arbor, thus yieldingly pressing the support wire 2| laterally against the inner wall of the arbor so as to firmly hold the support wire 2| and the wire screen element 20 in-position within the bulb.

It will be obvious that the shape of that portion of the support member 2| extending between 1. An electric incandescent lamp comprising a sealed glass bulb havinga reentrant stem provided with a tubular chamber open to the interior oi the bulb, a, pair of lead-in wires sealed through said stem and extending into the bulb, a filament in said bulb connected to said lead-in wires, a blackening collector in said bulb adjacent said filament, and support means secured at one end to said blackening collector and having its other end extending into said tubular chamber and resiliently engaging the walls of said chamber to hold the support means in place therein.

2. An electric incandescent lamp comprising a sealed glass bulb having a reentrant stem provided with a tubular chamber open to the interior of the bulb, a pair'of lead-in wires sealed through said stem and extending into the bulb, a filament in said bulb connected to said lead-in wires, a blackening collector in said bulb adjacent said filament, and a support member fastened to said blackening collector and having a straight end portion extending into said chamber and provided with a spring finger yieldingly engaging opposite sides of the chamber wall to resiliently hold the said end portion firmly against the chamber wall.

3. An electric incandescent lamp comprising a sealed glass bulb having a reentrant stem provided with a tubular glass extension projecting inwardly of the bulb, a pair of lead-in wires sealed through said stem and extending into the bulb, a filament in said bulb connected to said lead-in wires, 9. blackening collector in said bulb adjacent said filament, and a support member fastened to said blackening collector and having'a straight end portion extending into said tubular stem extension and provided with a spring finger yieldingly engaging opposite sides of th inner wall '01- said extension to resiliently hold the said end portion of the-support meniber firmly against the said inner wall of the extension.

4. An electric-incandescent lamp comprising a sealed "glass .bulb having a reentrant stem prothe end of the arbor l8 and the blackening collector 20 will depend on the shape of the particular filament employed. Thus, while the said intervening portion of the support member 2| may extend substantiallystraight up from the end of the arbor |6 where the filament, as in the case of the particular horseshoe-shaped filament 2 shown, does not intersect or lie closely adjacent the bulb axis, it may be necessary to bend or otherwise onset the support member 2| outwardly of the arbor-,l6 where the filament intersects or extends closely adjacent the bulb axis. 7

What I claim as new and desire to secure by Letters Patent of the United States is:

vided with a tubular chamber open to the interior of the bulb and having shoulders therein spaced longitudinally thereof, a pair of lead-in wires sealed through said stem and extending into the bulb, a filament in said bulb connected to said lead-in wires, 9. blackening collector in said bulb adjacent said filament, and a support member fastened to said blackening collector and having a straight end portion extending into said chamber and provided with a spring finger yieldingly engaging opposite sides of the chamber wall to resiliently hold the said end portion firmly against the chamber wall, said end'portion, further having stop means spaced longitudinally thereof and engageable with the said shoulders in said chamber to limit movement of the support member longitudinally of the chamber.

5. An electric incandescent lamp comprising a sealed glass bulb having a reentrant stem provided with a tubular chamber open to the interior oi the bulb and having shoulders therein spaced longitudinally thereof, a pair of lead-in wires sealed through said stem and extending into the bulb, a filament in said bulb connected to said lead-in wires, a blackening collector in said bulb adjacent said filament, and a support member fastened to said blackening collector and having a straight end portion extending into said chamber and provided with a spring finger yieldingly engaging opposite sides of the chamber wall to resiliently hold the said end portion firmly against the chamber wall, said spring finger toeether with the end of said support member innermost of said chamber providing spaced limiting stops engageable with the said shoulders in said chamber to limit movement of the support member longitudinally oi the chamber.

d. an electric incandescent lamp comprising a sealed glass bulb having a reentrant stem provided with. a tubular chamber open to the interior oi the bulb, a pair of lead-in wires sealed through said stem and extending into the bulb,

I t it in said bulb connected to said lead-in wires, a blackening collector in said bulb adjacent said filament, and a support member fastened to said blackening collector and having an ex tension of spring material extending into said id l and bent back upon itself to provide a retroverted portion, the free end of said retroverted portion being bent at an angle to provide a spring finger yieldingly engaging opposite sides at the chamber wall to resiliently hold the said extension firmly against the chamber wall.

it. an electric incandescent lamp comprising a sealed glass bulb having a reentrant stem provided with a tubular chamber open to the interior oi the bulb and having shoulders therein spaced longitudinally thereof, a pair of lead-in wires sealed through said stem andextending into the bulb, a filament in said bulb connected to said lead-in wires, 9. blackening collector in said bulb adjacent said filament, and a support member fastened to said blackening collector and having a spring wire extension projecting into said chamber and bent back upon itsel! to term a U-bend and provide a retroverted portion the tree end of which is bent at an angle less than 90 to provide a spring finger yieldingly engaging opposite sides of the chamber wall to resiliently hold the said wire extension firmly against the chamber wall, the free end 01 said spring finger and the U-bend in said wire extension constituting spaced limiting stops engageable with the said shoulders in said chamber to limit movement of the support member longitudinally of and restrain its withdrawal from said chamber.

8. An electric incandescent lamp comprising a sealed glass bulb having a reentrant stem provided with a tubular chamber open to the interior or the bulb, a pair of lead-in wires sealed through said stem and extending into the bulb, a filament in said bulb connected to said leadin wires, a blackening collector in said bulb adjacent said filament, and a spring wire support fastened at one end to said blackening collector and having its other end extending into said chamber and bent back upon itself to provide a retmverted portion, the free end of said retroverted portion being bent at an angle to provide a spring finger yieldingly engaging opposite sides or the wall to resiliently hold the spring wire support firmly against the chamber wall.

9.. An electric incandescent lamp comprising a sealed glass bulb having a reentrant stem pro vided with a press portion, a hollow glass arbor extending from said stem press portion inwardly of the bulb and having an inturned lip at its free end, a pair of lead-in wires sealed throng the said press portion of the stem and ex t 1; into the bulb, a filament in said bulb connects to said lead-in Wires, a blackening collector comprising a wire screen member in said bulb overlying said filament, and a spring wire support fastened at one end to said wire screen member and having its other end extending into mid arbor and bent back upon itself to form a IU=- bend and provide a retroverted portion the free end of which is bent at an angle less than to provide a spring finger yieldingly engaging opposite sides of the arbor wall to resiliently hold the wire support firmly against the arbor wall, the free end of said spring finger and the U-bend in said wire support constituting spaced limiting stops engageable respectively with the said inturned lip and the press portion of the stem to limit movement of the wire support longitudinally of and restrain its withdrawal from the arbor.

IRVING H. VAN HORN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 3,379,058 Anderson June 26, 1945 

